The Master volume MODs dont work properly on my Tweed 5E3 amp

[Kitarist]

So i tried 2 type of master volume mods. PRE and POST but both dont work properly. (1 MEG LOG POT)

I did everything as it shows on the schematics and it still doesnt work properly. https://robrobinette.com/5e3_Modifications.htm#Add_Master_Volume

What is happening that the volume mod is totally unusable when i just shift it a bit the amp already goes very loud and theres not much to work with. Is that normal? Both do the same thing.

I even checked again the operating voltages of the amplifier and everything works fine. Both mods are so simple really not sure why.. I even mesured and tested the pot.

So not sure what it would be causing this? Anyone got any ideas? Could be the output tubes? im using JJ 6V6 S tubes.

Thanks!!!

[MFowler]

I've done Bruce Collins Mission Amps master volume mod it uses a dual 1MA pot replacing the current first 1MA volume pot and coupling cap to .1uf and other changes.


Not sure I should post the layout.

[Willabe]

Not sure I should post the layout.

Why not?

[MFowler]

I'm no stranger to amplifier forums and once another person's layout is posted a shit storm arrives right after.


Why I mentioned the mod is so the OP can research and find the mod himself like I did without the problems associated with posting layouts.

[Willabe]

I think it's already been posted a few times here?

[Ed_Chambley]

Yes it has been posted here a few times.  I remember posting it a few times myself.  Don't remember a storm after, but you never know.

[Ed_Chambley]

Let's see, it is posted again.

[robrob]

Kitarist, are you sure the pot is a log or audio and not linear or reverse audio? Since both master volume configurations didn't work I'm thinking it's the pot.

[MFowler]

Here is the layout.

[ac427v]

I put a pre PI master volume on my mutated Princeton Reverb (similar phase inverter). Works great.
--Craig

[Kitarist]

I checked everything even changed different pot still same prob really not sure what could it be.

[ac427v]

I could not get the Robinette version to work without keeping the original 1 meg grid leak resistor and adding a 1 meg pot and another cap (.047). See my schematic for details if you want to try again.
--Craig

[Kitarist]

Ok i'll try that. Really not sure why both volume mods in robs website dont work :|

[tubenit]

I apologize, but I am not clear on what you have tried?   Have you tried this PPIMV?   I've used it on an amp very similar to a 5E3, and it worked excellent to my ears.

With respect, Tubenit

[Ed_Chambley]

Here is the layout.

MFowler,
Is this a pull switch pot or does the second volume become the main volume?  I have not seen this layout, but it look as if it incorporates what I have heard refereed to as a trick switch?  Have you tried this?  It looks interesting.  If you have done this, did you keep the 12Ay7 or change to 12Ax7?

[Ed_Chambley]

I apologize, but I am not clear on what you have tried?   Have you tried this PPIMV?   I've used it on an amp very similar to a 5E3, and it worked excellent to my ears.

With respect, Tubenit

This master volume I have found to be best for most amps and I have used it in a 5E3 incorporating the 6G3 tone stack.  The amp changes a LOT and you get a slower ramp up in volume.  You do lose the interaction of volume controls and the early onset of distortion which is what a lot of folks like about the Tweed Deluxe.  It doesn't make it a Brown Deluxe, but it gets sort of in-between.  The Ampeg mod ( Paul C mod for the PI) and a Blackface tone stack will make this amp sound a lot like a Carr Rambler.    If you want to make it into one you will need to Beef up the PT to run 5881's and add a Fender verb circuit.  I simply used the 1 tube verb.  Keep the voltages low since the rambler states 28 watts.

Now it is back mainly stock with a split cathode on V1 to get a good Humbucker tone simply because I decided to build a Carr knockoff.

Fun circuit to play with for sure. 

[MFowler]

MFowler,
Is this a pull switch pot or does the second volume become the main volume?  I have not seen this layout, but it look as if it incorporates what I have heard refereed to as a trick switch?  Have you tried this?  It looks interesting.  If you have done this, did you keep the 12Ay7 or change to 12Ax7?



This is a dual 1MA pot no push/pull. I have build an amp using this mod.

[Ed_Chambley]

MFowler,
Is this a pull switch pot or does the second volume become the main volume?  I have not seen this layout, but it look as if it incorporates what I have heard refereed to as a trick switch?  Have you tried this?  It looks interesting.  If you have done this, did you keep the 12Ay7 or change to 12Ax7?



This is a dual 1MA pot no push/pull. I have build an amp using this mod.

Thanks for the photos.  I got it now!  Gonna give it a try, looks interesting and the only way to know is build it.  I see you did use a 12Ax7.

Thanks again!

[robrob]

This is my recommended master volume for the 5E3 Deluxe:



It simply replaces the V2A 1M grid leak resistor with a 1MA pot. At max volume the circuit is unchanged.



You have to clip or remove the original 1M grid leak resistor.